A unilateral dermatomal venous malformation

Venous malformations (VMs) are the most common vascular malformations, forming 44% to 64% of all vascular malformations. We report a case of a patient suffering from unilateral dermatomal VM. The VM was strictly confined to the right C6 dermatome. We propose that unilateral dermatomal VM is a prime example of somatic mosaicism in vascular development. Unilateral dermatomal VM seems to have a similar pathogenesis to the Sturge-Weber syndrome and may also be caused by somatic mutations disrupting the development of skin veins.